The fabrication and identification of different inclusions are difficult in carbon fiber reinforced polymer (CFRP) laminates. In this paper, ultrasonic testing of inclusions, including artificial delaminations with Polytetrafluoroethylene (PTFE) and rich resin regions are studied by numerical simulation and experiment. Firstly, an ultrasonic reflection finite element model of multidirectional laminate considering elastic anisotropy of CFRP layers is established, and the time-domain signals of A-scan obtained by simulation and experiment are compared to prove the validity of the model. Then, PTFE inclusion with a width of 6 mm and thicknesses of 0.03– 0.40 mm and rich resin defects with thickness of 0.03– 0.85 mm are preset inside the CFRP laminate. The ultrasonic A-scan time-domain waveform of the defects is obtained by simulation, and the influences of the two kinds of defects thickness changes on the maximum amplitude and the kurtosis factor of ultrasonic signals are analyzed and compared. The results show that with increasing defect thickness, the maximum amplitude and kurtosis factor of defect signals both show a trend of first increasing, then decreasing and finally stabilizing. However, the maximum amplitude of rich resin defects is lower than that of PTFE inclusion, and the variation trend of rich resin defects kurtosis factor with thickness lags behind that of PTFE inclusion.